液态金属急冷过程中微观结构转变的研究

本文对液态金属Ａｌ在溶态及急冷过程中的微观结构及其转变进行了分子动力学模拟研究。发现在由ＨＡ（Ｈｏｎｅｙｃｕｔ－Ａｎｄｅｒｓｅｎ）健型指数所确定的双锥体原子团结构的数目随急冷温度变化的关系曲线上存在着二个明显的转变点。第一个点与熟知的玻璃转变温度Ｔｇ相吻合；而第二个点则为新发现的低温端相交点Ｔｇ２。这一结果为用分子动力学方法从微观层次上研究结构相变过程提供了一条新途径。

INVESTIGATION ON THE MICROSTRUCTURE TRANSITIONS IN THE RAPID COOLING PROCESSES OF LIQUID METALS

In this paper, a Molecular Dynamics simulation study has been made for the microscopicstructures and transitions of liquid metal Al in its melt state and rapid cooling processes. It has been found that there are two obvious transition points on the relation curve of the number of bipyramid aggregations determined by the HA (Honeycutt- Andersen ) index of bond- type with rapid cooling temperature. Of the two points the first one is consistent with the well konwn glasstransition temperature Ts,3 the second one should be a new phase transition temperature Tg2 atlow temperature end. this result will give a new way to study the structural transition at microscopic level by Molecular Dynamics method.